WATER-WAVE CONTROL BY A PITCHING PLATE

A new idea for controlling wafer waves is presented in this paper. A s ubmerged pitching plate is suggested as an active wave controller, and its feasibility is theoretically investigated, The two-dimensional pr oblem is formulated to deal with a fully submerged pitching plate fixe d at its middle point scattering an incoming monochromatic wave, and t he frequency of pitching is kept the same as that of the monochromatic wave, The method of matched eigenfunction expansions is used to analy ze the amplitudes of reflected and transmitted waves with and without pitching. The variation of wave reflection and transmission versus the dimensionless water depth, length of plate, and its depth of submerge nce is discussed. The characteristics of the pitching plate are like a fixed plate and still very sensitive to its submerged depth and physi cal dimensions. The pitching plate has its high performance by control ling the phase and magnitude of pitching. Based on the linear wave the ory, the wave force and moment are estimated, and their characteristic s are illustrated in this paper. It is found that pitching has no infl uence on wave force but induces additional moment on the plate.